leather creasing tool

I saw this on the flea market on Monday, and just had to get it for the low price!
I was told it was a leather worker's tool, but I didn't care at the time. I just saw it as a beautiful piece of ironmongery and treen, the handle is I think rosewood or possibly mahogany.
The name "Joseph Dixon" on the base of the metal and "4" on the blade gave me something to work with (pun intended! ;-)), and in no time I found the company was still going until recently, from the mid-1800's.
The tool is for creasing leather and is a number 4 tool (obviously!)
I think this one dates to the early 20th.C, and I really like it.
Not something you see every day...